Thrombosis And Embolism Flashcards
What is a Thrombosis
Formation of a solid mass of blood within the circulatory system
What is Virchow’s Triad
An explanation of how a thrombus forms, due to changes in 2 of;
Vessel wall
Blood flow
Blood components
What are 4 causes of vessel/ endothelial wall damage
Atheroma
Direct injury/ trauma
Inflammation
Myocardial Infarction
What are 2 possible problems with blood flow
Where are they more common and why
Stasis and Turbulent flow
In veins, due to reduced flow and valves
What are the problems with blood components
Identify 7 groups of people who may have this, and how?
Blood can enter a hypercoagulable state, becoming ‘sticky’
Pregnancy/ postpartum Post surgery Trauma/ fractures Burns Oral contraceptive users Cancer patients- Above 5 have increased fibrinogen and factor 8
Smokers- Activation of factor 12
Compare the appearances of arterial and venous thrombi
Arterial;
- Pale
- Granular
- Lines of Zahn (layers of Platelets, Fibrin, RBC, Platelet etc.)
- Low cell content
Venous;
- Soft
- Gelatinous
- Deep red
- Higher cell content
What are the outcomes/ complications of Thrombosis
- Lysis/ resolution
- Propagation
- Organisation
- Recanalise
- Embolise
What is propagation of a thrombosis
How do thrombi propagate in arteries and veins
Growth/ spread of a thrombosis
Proximally in veins
Distally in arteries
What is Organisation of a thrombosis
How does the vessel lumen end up
When the thrombus undergoes fibrous repair and forms a fibrous scar on the vessel wall
Remained obstructed
What is Recanalisation of a thrombosis
New channels formed through an organising thrombus, so that blood flow is partially re-established
What are the Venous and Arterial effects of a Thrombosis on the tissue
Venous;
- Oedema
- Ischaemia
- Infarction
- Congestion
Arterial;
- Infarction
- Ischaemia
What is an Embolism
What is the most common type of Emboli
The blockage of a blood vessel by Solid/ Liquid or Gas at a site distant from its origin
Thrombo-emboli
Compare the paths and end-results of thromboemboli in Arteries and Veins
In veins, flow from from smaller to larger vessels so will go through heart and embolise in pulmonary arteries
In arteries, flow from larger to smaller arteries, so can end up anywhere in systemic circulation, but mainly in lower limbs
Identify 7 Predisposing factors for a Deep Vein Thrombosis
- Immobility
- Post surgery
- Pregnancy/ Post-Partum
- Oral contraceptives
- Severe burns
- Cardiac failure
- Disseminated cancer
What are 3 outcomes of a Pulmonary Thromboembolism
- Large embolus in main Pulmonary Artery= Sudden death
- Small embolus in Peripheral Pulmonary Artery= Pulmonary Infarct
- Multiple small emboli= Pulmonary hypertension
